SQL & PL/SQL

Hi,

I am trying to split comma separated string. My table has more than 5 lacks data. I have tried the following SQL but its taking more than 5 minutes. Any Alternative solution to return data quickly ?

SELECT REGEXP_SUBSTR(order_id, '[^,]+', 1, LEVEL) order_id
          FROM order_detail
   CONNECT BY REGEXP_SUBSTR(order_id,'[^,]+',1,LEVEL) IS NOT NULL


SELECT REGEXP_SUBSTR(order_id, '[^,]+', 1, LEVEL) order_id
          FROM order_detail
  CONNECT BY LEVEL <= LENGTH(order_id) - LENGTH(REPLACE(order_id, ',')) + 1